JPS6356445B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooking appliance equipped with microwave heating means and hot air heating means, a so-called hot air circulation type microwave oven. Microwave heating has the disadvantage that browning cannot be achieved, and for this reason various microwave ovens have been proposed that are equipped with heaters to meet the demand for browning cooking. This type of cooker avoids increasing the size and cost in order to provide both functions.
Alternatively, care must be taken to ensure that one function is not sacrificed for the sake of the other.

The present invention has been made in view of the above circumstances, and aims to propose a cooking device that can effectively perform microwave heating and hot air heating, as well as suppress increases in cost. The embodiment will be explained in detail based on the drawings.

FIG. 1 is a schematic elevational sectional view of a cooking appliance according to the present invention. A stirrer 2 for microwave stirring and a sheathed heater 3 are installed at the top of the cooking chamber 1.
A hot air heating means consisting of a fan 4 and a fan 4 are installed. A drive shaft 4a of a fan 4 is rotatably arranged vertically through the upper wall 1a of the cooking chamber 1 using a bearing (not shown), and a pulley is attached to the upper end of the drive shaft 4a located outside the cooking chamber 1. 5 are fixed concentrically. In the internal space on the side of the cooking chamber 1, there is a magnetron 6 and a fan motor 6 for cooling it.
A pulley 7 is fixed to the output shaft of the fan motor 6a that projects upward, and a belt 8 is stretched between the pulley 7 and the pulley 5, and the rotation of the fan motor 6a Drive shaft 4
It is configured so that a can be rotated.

The drive shaft 4a passes through the heat shield plate 9, and its lower end is positioned in a downward recess 9a of the heat shield plate 9. The heat shielding plate 9 is made of a material such as ceramics or porcelain that allows microwaves to pass therethrough, has little microwave loss in that part, and has excellent heat resistance (particularly resistant to shocks caused by rapid heating and cooling).The drive shaft 9a A downward circular recess 9 centered on the central part through which the
The side wall of the recess 9a is tapered so that the upper part has a small diameter and the lower part has a large diameter, in accordance with the shape of the inner peripheral end of the blade portion 2a of the stirrer 2. The heat shielding plate 9 is mounted horizontally with its peripheral edge in contact with the peripheral wall of the cooking chamber 1 and fixed.

A fan 4 is attached to the lower end of the drive shaft 4a in the recess 9a, and a sheathed heater 3 is attached to the outer circumferential side of the rotation range of the drive shaft 4a and to the inner side of the side wall of the heat shield plate 9. are arranged to surround the fan 4 in a spiral manner. The sheathed heater 3 is energized by a lead wire (not shown) that is wired using the gap between the heat shield plate 9 and the stirrer 2 so as not to interfere with the rotation of the stirrer 2, which will be described later.

Both the sheathed heater 3 and the fan 4 are located within a recess 9a of the heat shielding plate 9, and the lower end opening of this recess is covered with a filter 10. Like the heat shielding plate 9, this filter 10 is made of ceramic, which has excellent microwave transparency and heat resistance.
It is made of porcelain or the like, and has a suction hole 10a with a diameter approximately equal to the inner diameter of the rotor blade of the fan 4 in the center, and a large number of small-diameter suction holes 10b in the outer peripheral side of the rotor blade. It is detachably attached to the lower end of the recess 9a. fan 4
sucks air from the food to be cooked side in the lower part of the cooking chamber through the suction hole 10a and sends it to the sheathed heater 3 on the outer periphery, and the heated air is then sent to the suction hole 10b.
The direction of rotation and the shape of the rotor blades are determined so that the food is sent from the food to the food to be cooked. In this way, oil, smoke, etc. contained in the wind flowing through the recess 9a adhere to the filter 10, particularly when passing through the suction hole 10b, and the hot air is purified.

The hole 9b in the center of the heat shield plate 9 has a slightly larger diameter than the drive shaft 4a, and the lower end of the stirrer support cylinder 11 is fitted therein using the gap between the two. The support tube 11 is made of oil-less metal or the like, has an inner diameter slightly larger than the outer diameter of the drive shaft 4a, and is fitted around the drive shaft 4a concentrically. A protrusion 11a of an appropriate size is provided around the upper part of the heat shield plate 9 near the lower end, and a stirrer 2
A core tube 2b formed at the center of the stirrer 2 is rotatably mounted on the support tube 1, and the weight of the stirrer 2 is supported by a protrusion 11a.

The microwaves emitted by the magnetron 6 reach the cooking chamber 1 through a waveguide (not shown).
Wind generated by the rotation of the fan 4 or fan motor 6a hits the rotary blades 2a and is stirred by the stirrer 2, which is driven by the stirrer 2. This causes the food to be cooked (not shown) to be placed on the food table 12. ) will be irradiated with microwaves evenly. Needless to say, the loss of microwaves due to the heat shield plate 9 and the filter 10 is extremely small, and the fan 4 performs a microwave stirring action by its rotation.

When the sheathed heater 3 is energized, as described above, as the fan 4 rotates, the air in the cooking chamber 1 enters the recess 9a from the suction hole 10a, passes through the position where the sheathed heater 3 is disposed, is heated, and is sucked out. Since it exits downward from the hole 10b, heat exchange between the sheathed heater 3 and the flowing air is performed effectively, and the indoor temperature increases quickly and can be easily maintained at a temperature of about 100 to 250°C. It becomes possible. In the cooker of the present invention, the hot air heating means consisting of the sheathed heater 3 and the fan 4 is located below the heat shield plate 9 to prevent its thermal influence from reaching the portion above the heat shield plate 9. , the materials of stirrer 2 and related parts have a maximum temperature of 250 to 300℃ in the cooking chamber.
However, it is sufficient that it can withstand temperatures of about 150°C. As the fan 4 rotates, the air in the cooking chamber 1 passes through the suction hole 10a, the fan 4 and the heater 3, and is efficiently guided to the suction hole 10b along the tapered side wall of the heat shield plate 9. The food is circulated and food is cooked efficiently.

FIG. 2 is a schematic vertical cross-sectional view showing another embodiment of the present invention, and this embodiment differs from that in FIG. 1 in the drive system of the fan 4, as shown in FIG. That is, the pulley 7 fixed to the output shaft of the fan motor 6a
is an interrupted pulley 2 fixed to a support shaft 21 rotatably supported vertically near the fan motor 6a.
2 and is connected by a belt 23 stretched between them. Pulleys 24a, 24b, and 24c for speed change with different diameters are integrally fixed to the upper part of the suspension pulley 22 of the support shaft 21, and these pulleys are moved by the rotation of the fan motor 6a. 2
4a, 24b, and 24c are rotatably driven.

The pulley 25 is rotatably attached to the shaft 26 and
The drive shaft 4a of the pulley 25 and the fan 4 is
A highly elastic belt 8' is stretched between the pulley 5 at the upper end of the belt 8'. The shaft 26 is rotatably inserted through the support pieces 27u and 27d at positions slightly below the upper end and slightly above the lower end so as to be slidable up and down, and the upper end is fixed at an appropriate position via a tension spring 28. It has been done. Also, the lower end is a tension spring 2
8 is connected to the plunger of the electromagnetic actuator 30 via a tension spring 29 that is stronger than 8. Support pieces 31u, 3 that support the support shaft 21 vertically
A tension spring 32 is provided between 1d and the support piece of the shaft 26.
u, 32d are interposed. Further, between the pulley 25 and the support piece 27d on the shaft 26, there is an arc-shaped guide hole 3 centered on the drive shaft 4a, which does not appear in FIG.
A guide piece 33 having a hole 3a is fixedly provided, and the shaft 26 is inserted through the guide hole 33a. A switch dog 26a is formed at the lower end of the shaft 26 to which one end of the spring 29 is locked, and a micro switch 34 is formed in the passage area of the switch dog 26a when the electromagnetic actuator 30 is actuated to move the shaft 26 downward. is provided, and pulley 25
The micro switch 34 is set at that position so that it is activated when the micro switch 34 becomes the same height as the pulley 24b. In this embodiment, as shown by the solid line, the pulley 25 is separated from the pulley 24a, etc., and power transmission to the fan 4 is cut off.
b or 24c, and the fan 4 can be used in four types of modes: low heat, medium heat, and high heat mode in which the fan 4 is rotated at low speed, medium speed, or high speed. That is, when using only microwave heating, the air rest mode is selected, but in this case, the support pieces 27u and 27d are connected to the springs 32u and 32 by means not shown.
The electromagnetic actuator 30 is kept in a non-operating state while being pulled and restrained in a direction in which it is pulled away from the support pieces 31u and 31d against the elasticity of d. As a result, the pulley 25 is maintained at the same height as the pulley 24a due to the balance between the tension springs 28 and 29, and the pulley 24a is separated from the pulley 24a, thereby cutting off power transmission from the fan motor 6a to the fan 4.

Next, in the case of low heat mode, electromagnetic actuator 3
0 releases the restraint of the support pieces 27u and 27d while remaining in the inactive state. Then, the pulley 25 comes into rolling contact with the small diameter pulley 24a, and the fan 4 rotates at a low speed. Next, in the case of medium heat mode, the electromagnetic actuator 30 is activated to pull the shaft 26 downward, and the switch dog 26a contacts the micro switch 34 to activate it and stop the pulling, while the support piece 27u, 27d is released, so that the pulley 25 becomes the medium diameter pulley 2b.
The fan 4 will rotate at a medium speed. Next, in the case of ignition mode, the electromagnetic actuator 30 is activated to pull the shaft 26 to its lower limit operating range, while supporting pieces 27u, 27d
release the restraints of This brings the pulley 25 into rolling contact with the large-diameter pulley 24c, causing the fan 4 to rotate at high speed.

Although the horizontal distance between the pulley 25 and the pulley 5 is kept constant by the guide hole 33a, the actual distance varies slightly as the shaft 26 moves up and down, but this is absorbed by the elasticity of the belt 8'. Ru.
Furthermore, the pulley 25 is configured to always move through the wind rest mode.

When the rotational speed of the fan 4 is configured to be adjustable as described above, it becomes possible to cook food according to the food to be cooked. That is, FIG. 4 shows a point P approximately in the center of the cooking chamber 1.
This shows the results of measuring the temperature over time, and various cooking methods are possible by utilizing the difference in temperature rise rate and the difference in saturation temperature.

As described above, the cooking device according to the present invention is a cooking device equipped with a microwave heating means and a hot air heating means, in which a heater and a microwave stirring device are installed below the microwave stirring stirrer arranged in the upper part of the cooking chamber. The invention is characterized in that it is equipped with a hot air heating means consisting of a fan, and a heat shielding plate made of a microwave transparent material is interposed between the hot air heating means and the stirrer. Microwave stirring is performed, allowing for more uniform microwave heating.

On the other hand, when using hot air heating means, the hot air heating means is provided below the stirrer, so the food can be heated efficiently without the hot air being blocked by the stirrer. Moreover, in such a configuration, since a heating shield plate is provided between the hot air heating means and the stirrer, the stirrer does not need to be made of a heat-resistant material, and an increase in cost can be avoided. Then, in 1983, a fan for heating hot air was also used as a microwave antenna.
-69849, but unlike this, there is no control over the electrical structure of the fan, making it highly practical.

Furthermore, if the fan is driven by an electric mechanism that can regulate the speed, it is possible to provide hot air to the food according to the cooking mode, and in this case, hot air heating can be performed without being interrupted by the stirrer. Parts costs can be suppressed. It goes without saying that, unlike the above-described embodiments, if the fan is rotated even in the case of microwave heating, the effect of uniformly performing microwave heating can be achieved.

[Brief explanation of drawings]

FIG. 1 is a schematic elevational sectional view of a cooking device of the present invention, FIG. 2 is a schematic elevational sectional view showing another embodiment of the invention, FIG. 3 is a perspective view schematically showing the main parts, and FIG. Figure 4 is a graph showing the temperature-time characteristics. 1... Cooking chamber, 2... Stirrer, 3... Sheathed heater, 4... Fan, 4a... Drive shaft, 6...
Fan motor, 9... heat shielding plate, 9a... recess,
10... Filter, 11... Stirrer support tube, 2
4a, 24b, 24c...speed change pulleys.

Claims (1)

[Scope of Claims] 1. In a cooking device equipped with a microwave heating means and a hot air heating means, a hot air provided by a heater and a fan that also serves as microwave stirring is placed below a microwave stirring stirrer disposed in the upper part of the cooking chamber. 1. A cooking appliance comprising a heating means, and a heat shielding plate made of a microwave transparent material interposed between the hot air heating means and a stirrer. 2. The cooking appliance according to claim 1, wherein the heat shield plate has a shaft for driving the fan inserted therethrough. 3. A heater is arranged around the outer periphery of the fan, and the heat shielding plate has a recess opening downward in the center thereof, and the fan and the heater are housed in the recess, according to claim 1. cooker. 4. In a cooking device equipped with a microwave heating means and a hot air heating means, a hot air heating means consisting of a heater and a fan that serves both as a heater and a microwave stirring fan is provided below the microwave stirring stirrer disposed in the upper part of the cooking chamber. A heat shielding plate made of a microwave transparent material is interposed between the hot air heating means and the stirrer,
A cooking appliance characterized in that the fan uses a magnetron cooling fan motor as a drive source, and a transmission mechanism capable of speed regulation is provided between the fan and the fan motor.